KR101104252B1 - Composition of foam midsole compound can adhere with Non-UV and preparing method of foam midsole using it - Google Patents

Abstract

The present invention is a blend of an ethylene vinyl acetate copolymer, an ethylene acrylic copolymer, an alpha olefin copolymer and an ethylene acrylic rubber as a mixed substrate, and a foaming agent, a crosslinking agent, various additives, and the like. By manufacturing the foam for shoe midsole using the compound prepared by using the mixed mixture, by applying the primer immediately without the ultraviolet (UV) treatment, which is a conventional adhesive process, when the shoe sole foam adheres to the sole Non-ultra-adhesive foam compound composition for non-ultraviolet adhesion, and a method for manufacturing a shoe midsole foam using the same, characterized by having excellent mechanical properties and adhesion compared to the foam for the present invention, while reducing the conventional process step Adhesive strength equivalent to or higher than that of the shoe midsole foam manufactured by It is possible to prepare the foam composition, and the productivity is improved because the complete adhesion is achieved only by treating the primer without the ultraviolet (UV) treatment rather than the conventional ultraviolet (UV) bonding process, and in particular, the human body by ultraviolet (UV) irradiation Due to the elimination of harmful processes and the shortening of the process, it is an advantage that it is an environmentally friendly method that can shorten the product manufacturing time and save expensive process costs.

Non-UV, Shoe Midsole, Foam, Adhesive, Ethylene Vinyl Acetate Copolymer, Acrylic Copolymer, Environmentally Friendly Method

Description

Composition of foam midsole compound can adhere with Non-UV and preparing method of foam midsole using it

The present invention is a blend of an ethylene vinyl acetate copolymer, an ethylene acrylic copolymer, an alpha olefin copolymer and an ethylene acrylic rubber as a mixed substrate, and a foaming agent, a crosslinking agent, various additives, and the like. By manufacturing a shoe midsole foam using the compound prepared using the mixed mixture, the shoe midsole foamed by this compound is treated only with a primer without ultraviolet (UV) treatment. It relates to a non-UV adhesive midsole foam compound composition characterized by having excellent mechanical properties and adhesion compared to the foam for the shoe and a method for producing a foam for shoe midsole using the same.

In general, the shoe industry is classified as a representative labor-intensive industry in which people are directly involved in almost all processes from parts manufacturing to final shoes. Therefore, the longer the manufacturing process, the higher the labor cost and the higher the production cost of the product. Therefore, the production of low-priced products depends on the late country, while the industrial structure is reorganized based on technology-intensive functional materials and components. It is creating added value. Through the change of the industrial structure as described above, the necessity of new technology development has been recognized, and the diversification and high functionalization of products have been steadily made by riding on this atmosphere.

As a result, the number of parts in a pair of shoes has been beyond imagination, and the material has also been diversified to use various plastic products in addition to the rubber materials used in the past. Adhesion is carried out through the process to manufacture the final product. In addition, in large companies such as Nike, the recognition of workers' human rights and the working environment has changed, so the importance of the adhesive element becomes more important because the existing adhesive effect has gradually shifted to the use of water-based adhesives instead of better solvent-based adhesives. There is a situation.

If you look at the structure of sports shoes that people wear a lot, it can be divided into the upper part surrounding the foot and the sole part supporting the bottom. In the shoe structure, the most problematic part is the sole part, which is the sole part, and the various parts are assembled, thereby completing the product through various processes.

The sole part is divided into the outer sole and the inner insole and the midsole. The adhesion of the upper part of the shoe to the midsole connecting the outermost part of the shoe is the most important. Done. The midsole consists mostly of foams, and these foams can be manufactured by directly forming the primary molded products at high temperature and high pressure (injection method) or by cutting them to a constant size and applying secondary pressure and heat to form secondary moldings. Bonding becomes difficult due to the formation of the surface layer during the molding process. Therefore, in order to adhere these foams, a plurality of pretreatment processes are performed. Generally, the foams are bonded through a buffing-washing-drying-pretreatment agent-drying-ultraviolet treatment-adhesive coating-drying-pressing process.

Among these processes, the primer treatment process and the ultraviolet treatment process have excellent adhesion effects, but chemical treatment methods using organic solvents, which not only generate volatile organic compounds and strong ultraviolet rays that are harmful to the human body, but also increase the production cost according to the increase of time and workforce. I have the same problem.

Therefore, in order to remedy these shortcomings, research into various adhesive methods that can replace the ultraviolet (UV) process has been started, and attention is being focused on the development of foams that can be bonded without ultraviolet (UV) treatment. Such foams are being developed through surface modification of foams, development of adhesives with excellent adhesiveness, blends of hydrogenated resins and graft polymers, and the like. In particular, in the shoe industry, non-UV primers have been developed and adhered to the midsole foams and soles, but they are difficult to improve and poor adhesion results. There is a tendency to manufacture a product capable of non-ultraviolet treatment adhesion through.

Korean Patent No. 10-0561652 proposes a technology for non-UV EVA foam by the EVA compound composition, in the case of the above patent 15 to 20 parts by weight of polyurethane in 100 parts by weight of EVA Addition to improve adhesion. However, polyurethane, which is an adhesive effect element, has a problem of durability due to hydrolysis problem when used for shoe midsoles, and it is not actually specified because split tear, which is the largest factor, is not specified in consideration of adhesive strength. Reliability on strength was not taken into account.

In addition, Korean Patent No. 10-0607131 describes a technique for improving the adhesive force by adding DCPD resin to the EVA compound composition. The above patent is to produce irregularities on the surface of the foam by using an organic solvent after manufacturing the EVA foam, the organic solvent has a low boiling point and rapid evaporation risk of poisoning, which may be harmful to the human body and may act as a deterrent to the working environment. .

Therefore, in view of these considerations, the process of adhering the foam through the non-UV process should be carried out simultaneously with the improvement of the process and the study of the composition to have the physical properties and the adhesion improvement effect of the shoe sole foam. The present inventors have completed the present invention by developing a foam composition for shoe soles suitable for adhesion without ultraviolet (UV) treatment.

The present invention has been studied in various ways to solve the problems of the prior art as described above, to improve the adhesive properties by applying the adhesion improving element to the foaming raw material itself to be bonded, for this purpose ethylene vinyl acetate For injection molding to maximize the physical properties of the composition and the processability of the compound through a blended blend of a copolymer, an ethylene acrylic copolymer, an alpha-olefin copolymer and an ethylene acrylic rubber. Injection Phylon) compound, and by using the same to prepare a foam for shoe midsole, it is easy to use, non-UV adhesive capable foam compound composition for non-UV, characterized in that the excellent adhesive properties and the same To provide a method for manufacturing a shoe sole foam using Zero.

In the present invention, the shoe sole foam prepared using the shoe sole foam compound composition prepared according to the above method can maintain a strong adhesive force only by applying a primer without irradiating UV (UV) when adhering to the sole. It is another object of the present invention to provide a non-UV adhesive compound composition for shoe midsoles and a method for manufacturing a shoe sole foam using the same.

Therefore, the present invention has the advantage that the cost is reduced for the subcontractor and the production line is simplified because it can be used in-line when used in the finished factory. In addition, there is no harmful ultraviolet radiation to the human body is characterized by an environmentally friendly method that can maintain a comfortable working environment.

The present invention for achieving the above object in the foam composition for shoe soles,

2.5 to 7.0 parts by weight of foaming agent and 0.5 to 0.8 weight of crosslinking agent based on 100 parts by weight of a mixed substrate blend of ethylene vinyl acetate copolymer, ethylene acrylic copolymer, alpha-olefin copolymer and ethylene acrylic rubber Part, 0.5 to 1.0 parts by weight of crosslinking aid, 1 to 5 parts by weight of metal oxide, 1 to 2 parts by weight of stearic acid, 0.1 to 1.0 parts by weight of pigment, 1 to 5 parts by weight of titanium oxide, and 5 to 10 parts by weight of adhesion improving agent A non-UV adhesive compound composition for shoe soles capable of non-UV adhesion, and a method for manufacturing a shoe sole foam using the same as a problem solving means.

And the mixed substrate blend is 30 to 60 parts by weight of ethylene vinyl acetate copolymer, 5 to 12 parts by weight of ethylene acrylic copolymer, 20 to 35 parts by weight of alpha-olefin copolymer and ethylene acrylic rubber 15 It is preferable that it consists of ˜23 parts by weight,

In addition, the mixture may further include 1 to 15 parts by weight of the polylactic acid copolymer based on 100 parts by weight of the blend.

As described above, according to the present invention by the above-mentioned means for solving the problem, a compound composition for foam having a bonding strength that is equal to or higher than that of a shoe midsole foam manufactured by a conventional method while being simpler in manufacturing process than the conventional process is used. It is possible to manufacture the foam for the shoe midsole, and because the complete adhesion is achieved even by a simple adhesion process of the primer treatment-adhesive application rather than the conventional multi-step adhesion process, productivity is improved, in particular a separate device for ultraviolet (UV) irradiation The cost of purchasing and leasing is reduced and there is no harmful process to the human body by ultraviolet irradiation generated during ultraviolet (UV) irradiation.

The present invention for achieving the above effect relates to a foam compound composition for shoe midsole capable of non-UV adhesion and a method for manufacturing a foam for shoe midsole using the same, the present invention is ultraviolet (UV) which is a conventional method It is characterized in that the compound composition for the sole sole foam, characterized in that the adhesive properties with the outsole is excellent by simply treating the primer without going through the irradiation step.

In the non-ultraviolet adhesive foam composition for shoe soles of the present invention, in the foam composition for shoe midsoles,

2.5 to 7.0 parts by weight of blowing agent and 0.5 to 0.8 parts by weight of crosslinking agent based on 100 parts by weight of a mixed substrate blend of ethylene vinyl acetate copolymer, ethylene acrylic copolymer, alpha olefin copolymer and ethylene acrylic rubber. , 0.5 to 1.0 parts by weight of crosslinking aid, 1.0 to 5.0 parts by weight of metal oxide, 1 to 2 parts by weight of stearic acid, 0.1 to 1.0 parts by weight of pigment, 1 to 5 parts by weight of titanium oxide, and 5 to 10 parts by weight of adhesion improving agent. do.

And the mixed substrate blend is 30 to 60 parts by weight of ethylene vinyl acetate copolymer, 5 to 12 parts by weight of ethylene acrylic copolymer, 20 to 35 parts by weight of alpha-olefin copolymer and ethylene acrylic rubber It is characterized by consisting of 15 to 23 parts by weight.

Looking in more detail the components of the foam compound composition for shoe soles according to the present invention.

First, in the mixed substrate blend used as the substrate in the present invention, the ethylene vinyl acetate copolymer (EVA) is preferably used in an amount of 30 to 60 parts by weight, and when the mixed amount of the ethylene vinyl acetate copolymer is less than 30 parts by weight, There is a possibility that a marked drop in mechanical strength may appear, and when it exceeds 60 parts by weight, the properties of other polar polymers are less likely to appear, and there is a possibility that the adhesive properties may be degraded. And the vinyl acetate content is 3.0 to 42.0% by weight, it is preferable to use a melt flow index of 0.5 ~ 6.0 g / 10min.

The ethylene vinyl acetate copolymer usable in the present invention is not particularly limited, and one or more of ELVAX3388, ELVAX2288, ELVAX360, ELVAX462 (Dupont, USA), EVA1317, EVA1326 can be selected and used.

In addition, it is preferable to use 5 to 12 parts by weight of the ethylene acrylic copolymer, and when the mixed amount of the ethylene acrylic copolymer is less than 5 parts by weight, there is a problem in that the adhesion improvement effect is lowered. There is a problem that the molding time is long due to the delay. And it is preferable to use an acrylate content of 10 to 28% by weight and a melt flow index of 0.4 to 7.0 g / 10min.

The ethylene acrylic copolymer that can be used in the present invention is not particularly limited, and may be used by selecting one or more of Elvaloy 3427AC, 2116AC, 1224AC, and 1820AC (Dupont, USA).

In addition, it is preferable to use 20 to 35 parts by weight of the alpha-olefin copolymer, and when the mixing amount of the alpha-olefin copolymer is less than 20 parts by weight, there is a problem that the mechanical strength is lowered. If the amount exceeds 35 parts by weight, the hardness is increased, and there is a problem that the extrusion characteristics are lowered during compounding. And it is preferable to use a melt flow index of 1.0 ~ 5.0 g / 10min.

The alpha-olefin copolymer usable in the present invention is preferably selected from one or more of low density polyethylene, ethylene octene copolymer, and ethylene butene copolymer.

In addition, it is preferable to use 15 to 23 parts by weight of ethylene acrylic rubber, and when the mixing amount of the ethylene acrylic rubber is less than 15 parts by weight, there is a slight problem of adhesive effect, and when it exceeds 23 parts by weight, the crosslinking density is significantly lowered. There is a problem that the physical properties are degraded. And in the case of ethylene acrylic rubber, the specific gravity is 1.05 ~ 1.07g / cc, it is preferable to use the one having a pattern viscosity of 20 ~ 24 (1 + 4 at 100 ℃).

The blowing agent is an azo compound such as azodicarbonamide having a decomposition temperature of 130 ° C. to 200 ° C., a nitroso compound such as N, N'-dinitrosopenta methylenetetraamine, azobisisobutyronitrile or p-toluene sulphate. It is preferable to select and use 1 type or more from the group which consists of a ponyl hydrazine, a p, p'- oxybis (benzenesulfonyl hydrazide) type compound, and a diazoamino azobenzene.

In addition, the addition amount of the blowing agent is preferably used 2.5 to 7.0 parts by weight based on 100 parts by weight of the mixed substrate blend in consideration of the foaming ratio and specific gravity of the foam, the amount of blowing agent is the amount of decomposition gas (for example, 200 in the case of ADCA system) ~ 230ml / g, denatured ADCA system is determined according to 130 ~ 170ml / g, 240ml / g for DPT system, 125ml / g for OBSH). If the amount of the blowing agent is less than 2.5 parts by weight, the resulting foam has a high hardness and high specific gravity. If the amount of the blowing agent is more than 7.0 parts by weight, the hardness is low and the physical properties are deteriorated. Sudden expansion above the high temperature viscoelastic limit of s causes a problem of forming unstable foam cells in which the foam bursts.

In addition, the crosslinking agent is a peroxide crosslinking agent capable of sufficiently trapping the decomposition gas generated above the decomposition temperature of the blowing agent and imparting high temperature viscoelasticity to the resin, with respect to 100 parts by weight of the mixed substrate blend in consideration of the physical properties of the foam. It is preferable to use 0.5-0.8 weight part. If the amount of the crosslinking agent is less than 0.5 parts by weight, the crosslinking is insufficient to maintain the high temperature viscoelasticity of the resin during decomposition of the foaming agent. If the amount of the crosslinking agent exceeds 0.8 parts by weight, the appearance of the foam becomes poor due to overcrosslinking, and the hardness is rapidly increased. It is not suitable for use. In addition, when the content of the crosslinking agent increases, the degree of crosslinking increases, so that the compression set property is improved, whereas the tearing tear property tends to decrease.

The peroxide crosslinking agent is preferably a 10-minute half-life temperature of 130 ~ 200 ℃, for example t-butyl peroxy isopropyl carbonate, t- butyl peroxy laurate, t- butyl peroxy acetate , Di-t-butyl diperoxy phthalate, t-dibutyl peroxy maleic acid, cyclohexanone peroxide, t-butyl cumyl peroxide, t-butyl hydroperoxide, t-butyl peroxy benzoate, dicumyl peroxide, 1 , 3-bis (t-butylperoxyisopropyl) benzene, methylethylketone peroxide, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, di-t-butylperoxide, 2,5-dimethyl-2,5-di (t-butylperoxy) -3-hexane, n-butyl-4,4-bis ( 1 type or more can be selected and used from the group which consists of t-butyl peroxy) valerate, or (alpha), (alpha) -bis (t-butylperoxy) diisopropyl benzene.

In addition, the crosslinking aid is to obtain an appropriate crosslinking structure for shortening the molding time and improving durability when crosslinking the peroxide, and the amount of the crosslinking aid is preferably 0.5 to 1.0 parts by weight based on 100 parts by weight of the mixed substrate blend. If the amount is less than 0.5 parts by weight, there is little effect of promoting crosslinking, and if it exceeds 1.0 parts by weight, there is a possibility that normal foaming may not be possible due to overcrosslinking.

Examples of the crosslinking aid include a small amount of sulfur, triallyl cyanurate, triallyl isocyanurate, trimethylol, propane trimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, and butylene glycol. One or more types can be selected and used from the group which consists of an acrylate, butylene glycol dimethacrylate, a metal acrylate, and a metal methacrylate.

In addition, the metal oxide is preferably used in an amount of 1 to 5 parts by weight based on 100 parts by weight of the mixed substrate blend to help the processing characteristics of the foam, and to improve physical properties. If the amount of the metal oxide used is less than 1 part by weight, there is a problem in that the foaming property of the blowing agent is weak. When the amount of the metal oxide is more than 5 parts by weight, the dispersion property of the metal oxide is weak. Specifically, the metal oxide may be selected from one or more selected from the group consisting of cadmium oxide, zinc oxide, magnesium oxide, mercury oxide, tin oxide, lead oxide or calcium oxide. In particular, the metal oxide also serves as a decomposition aid for the blowing agent.

And stearic acid serves to improve the crosslinking and foaming properties and work characteristics in the foam of the present invention, it is preferable to use 1 to 2 parts by weight based on 100 parts by weight of the mixed substrate blend, if the amount is 1 If it is less than the weight part, the crosslinking and foaming properties are weak, and the workability is also weak due to the adhesive property of EVA. If the weight is more than 2 parts by weight, mechanical properties of the foam are deteriorated.

In addition, the pigment used to impart color to the foam is preferably used in an amount of 0.1 to 1.0 parts by weight based on 100 parts by weight of the mixed material blend, and the amount actually used depends on the design and color of the product. If it is less than 0.1 part by weight, the desired color cannot be obtained. If it is more than 1.0 part by weight, there is a problem of a price increase of the product.

And titanium oxide is used as a pigment for giving a white color to a foam, and it is preferable to use 1-5 weight part with respect to 100 weight part of mixed base blends.

As the adhesion improving agent, alcohols, phenols, and other functional groups having a hydroxy group having a boiling point of 120 ° C. or higher of Korean Patent No. 10-0635261 (announced on October 23, 2006) proposed by the present applicant and registered in advance. 10 to 130 parts by weight of the combined organic compound is obtained by being supported on 100 parts by weight of the porous body having a specific surface area of 2 m 2 or more, and thus the detailed description thereof is omitted in the present invention. In the present invention, a mixture of a glycol (glycol) and an alpha-olefin (α-olefin) copolymer, which is a reactive substance, was used. As a result, a release effect was exhibited on the processing equipment. To overcome this problem, surface-treated silica masterbatches were used to solve the problem. In this case, in the case of the silica master batch for improving adhesion, it is preferable to use 5 to 10 parts by weight based on 100 parts by weight of the mixed substrate blend in consideration of the amount of the alpha-olefin copolymer. When the amount of the adhesion improving agent is less than 5 parts by weight, the effect of improving the adhesive properties is insignificant, and when the amount of the adhesion improving agent is more than 10 parts by weight, the workability is lowered and the crosslinking effect is affected, making the foam shape difficult.

In addition, the present invention may further include 1 to 15 parts by weight of the polylactic acid copolymer with respect to 100 parts by weight of the mixed substrate blend. The polylactic acid copolymer, which is the reactive additive, serves as an adhesion improving agent. When the amount of the polylactic acid copolymer used is less than 1 part by weight, the effect of improving the adhesion is insignificant. Becomes high and foaming becomes difficult, and the shape of the foam becomes difficult. In addition, the commercialization of the polylactic acid copolymer, the mechanical strength such as split tear (split tear) is shown to improve the ability to produce a foam of better performance.

In addition, the above-mentioned base material, foaming agent, crosslinking agent, metal oxide, stearic acid, and other additives commonly used as foaming aids, fillers and the like may be added as a constituent for producing a foam for footwear according to the present invention.

Hereinafter, a method for preparing a shoe sole foam using the shoe compound foam composition for shoe midsole according to the present invention having the above components will be described in detail.

The present invention provides a method for producing a foam for shoe midsole,

1) 2.5 to 7.0 parts by weight of blowing agent, 0.5 to 0.8 parts by weight of crosslinking agent, 0.5 to 1.0 parts by weight of crosslinking aid, 1 to 5 parts by weight of metal oxide, 1 to 2 parts by weight of stearic acid, pigment 0.1 based on 100 parts by weight of the mixed substrate blend. And kneading to 1.0 parts by weight, 1 to 5 parts by weight of titanium oxide, and 5 to 10 parts by weight of an adhesion improving agent through a kneader, and then manufacturing them into a compound for shoe sole foam in a pellet form that can be injection molded through an extruder;

2) by injection molding the compound prepared in step 1) at 170 ~ 172 ℃, 140 ~ 160 kg / cm ² for 6 to 8 minutes to produce a shoe sole foam, or

2 ') The foam prepared by first pressing the compound prepared in step 1) at 150 to 170 ° C. and 140 to 160 kg / cm ² for 11 to 15 minutes at 150 to 160 ° C. and 140 to 160 kg / cm ² . Cooling and compressing after the second press is characterized in that the step of producing a foam for the shoe midsole.

The shoe sole foam manufactured through the steps 1), 2) or 1), 2 ') is not a complicated process of undergoing a conventional buffing-washing-drying-pretreatment application-drying-ultraviolet treatment-adhesive application process. It is characterized by an adhesive process which can be easily adhered to the outsole by three steps of the application of the cleaning agent pretreatment and the application of the adhesive.

And in the step 1) it may further comprise 1 to 15 parts by weight of the polylactic acid copolymer with respect to 100 parts by weight of the mixed substrate blend to produce a compound for shoe midsole foam.

Referring to step-by-step description of the method for manufacturing a shoe sole foam compound for shoes in the present invention and the foam for shoe soles using the same.

First, the step of preparing a foam compound composition for shoe midsole,

First, a mixture in which various additives are added with respect to 100 parts by weight of the mixed substrate blend is ban-bury mixer or kneader at a temperature range above the melting point and below the decomposition point of the crosslinking agent and the blowing agent, that is, 80 to 110 ° C. (kneader), open roll mill (open roll mill) is kneaded sufficiently to form a mixture of mixed substrate brand.

Since the kneaded material has already been described above, the description thereof will be omitted.

This kneaded product is made into a foam compound for shoe soles in the form of pellets which can be injection molded through an extruder. Then, injection molding is performed using the pellet compound. When the foam is manufactured by the injection molding, injection molding is carried out in order by adjusting the injection mold to one foam in consideration of the physical properties and colors required for each part of the shoe sole.

Here, the temperature of the injection part is 70 ~ 105 ℃, which is enough to melt and flow the kneaded material, the temperature and pressure of the injection mold is 170 ~ 172 ℃ temperature and 140 ~ 160 is easy to flow into the mold without kneaded material is foamed It is carried out under a pressure of kg / cm ² . In addition, in the injection molding, two kinds of compositions having different foaming ratios may be dry blended by a tumbler at a constant ratio to prepare a foam having a constant foaming ratio.

Alternatively, the foam prepared by first pressing the compound prepared in the form of pellets capable of injection molding through the extruder at a temperature of 150 to 170 ° C. and a pressure of 140 to 160 kg / cm ² for 11 to 15 minutes. After the second press under a temperature of 150 ~ 160 ℃ and a pressure of 140 ~ 160 kg / cm ² by cold compression can be produced a foam for shoe soles having a constant foaming ratio.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited by Examples.

Examples 1, 2 and Comparative Example 1 below were based on the foams prepared by injection molding the foam compound composition for shoe soles prepared according to the component ratios of the following [Table 1] by controlling the foaming agent content at the same composition ratio It is possible to produce foams by compression molding.

(Example 1)

30 parts by weight of ethylene vinyl acetate copolymer, 12 parts by weight of ethylene acrylic copolymer, 35 parts by weight of alpha-olefin copolymer, and 100 parts by weight of a mixed substrate blend based on 23 parts by weight of ethylene acrylic rubber, 3 parts by weight of zinc oxide, 1 part by weight of stearic acid, 4 parts by weight of titanium oxide, 0.5 part by weight of pigment, and 5 parts by weight of an adhesion improving agent were added and mixed for about 10 minutes in a kneader at 90 to 110 ° C. A kneaded product was prepared by adding 0.7 parts by weight of the crosslinking agent, 0.5 parts by weight of the crosslinking aid and 3.3 parts by weight of the blowing agent in a roll mill having a surface temperature of 80 to 90 ° C. The kneaded mixture mixed with the crosslinking and blowing agent was prepared into a pellet-type compound through an extruder, and these compounds were injection molded at an injection part temperature of 80-82-83-85 ° C and an injection mold temperature of 172 ° C. Was prepared. The prepared foams were evaluated for their properties by the method specified in the test examples, and their adhesion was treated with primers on the specimens, in which the primers used could be used as well as non-toxic primers. After that, a water-soluble polyurethane adhesive (Dongsung NSC Co., Ltd., Bond Ace W-01, W-104) was used. After mixing 5% of the curing agent, W-104 was first applied to the foam, followed by drying at 60 ° C. for 5 minutes. W-01 was applied again and dried at 60 ° C. for 5 minutes, and then pressed with rubber for outsole to measure adhesion. Using a universal testing machine (UTM, Zwick model 1435) was measured at a speed of 100mm / min.

(Example 2)

60 parts by weight of ethylene vinyl acetate copolymer, 5 parts by weight of ethylene acrylic copolymer, 20 parts by weight of alpha-olefin copolymer, and 100 parts by weight of the mixed substrate blend based on 15 parts by weight of ethylene acrylic rubber, 3 parts by weight of zinc oxide, 1 part by weight of stearic acid, 4 parts by weight of titanium oxide, 5 parts by weight of an adhesion improving agent, 5 parts by weight of polylactic acid, and 0.5 parts by weight of pigment were added and mixed for about 10 minutes in a kneader at 90 to 110 ° C. . A kneaded product was prepared by adding 0.8 parts by weight of the crosslinking agent, 0.5 parts by weight of the crosslinking aid and 3.8 parts by weight of the blowing agent to the mixture in a roll mill having a surface temperature of 80 to 90 ° C. The kneaded mixture mixed with the crosslinking and blowing agent was prepared into a pellet-type compound through an extruder, and these compounds were injection molded at an injection part temperature of 80-82-83-85 ° C and an injection mold temperature of 172 ° C. Was prepared. The prepared foams were evaluated for their properties by the method specified in the test examples, and their adhesion was treated with primers on the specimens, in which the primers used could be used for low-toxic primers as well as for general solvent type primers. After that, a water-soluble polyurethane adhesive (Dongsung NSC Co., Ltd., Bond Ace W-01, W-104) was used. After mixing 5% of the curing agent, W-104 was first applied to the foam, followed by drying at 60 ° C. for 5 minutes. W-01 was applied again and dried at 60 ° C. for 5 minutes, and then pressed with rubber for outsole to measure adhesion. Using a universal testing machine (UTM, Zwick model 1435) was measured at a speed of 100mm / min.

(Comparative Example 1)

3 parts by weight of zinc oxide, 1 part by weight of stearic acid, 4 parts by weight of titanium oxide, based on 100 parts by weight of ethylene vinyl acetate copolymer, which is conventionally widely used as a material for footwear foams, in order to highlight the effects of the embodiments of the present invention. Part by weight, 0.5 part by weight of pigment was added to form a foam in the same manner as in Example 1. The crosslinking agent used at this time was 0.625 weight part, 0.5 weight part of crosslinking adjuvant, and 3 weight part of foaming agents.

The method for adhering the shoe sole foam prepared by the method of Examples 1 to 2 and Comparative Example 1 is a water-soluble polyurethane adhesive (Dong NSC Co., Ltd., Bond Ace W-01, W-104) After mixing 5% of the curing agent, W-104 was first applied to the foam, and then dried at 60 ° C for 4 minutes, then W-01 was applied again, and dried at 60 ° C for 5 minutes to be compressed with the outsole rubber for adhesion. Was measured. Currently, the industry shows an adhesive strength of more than 2.5kg / cm and requires that the adherend is destroyed when peeling,

                                                         (Unit: parts by weight) division Example Comparative example One 2 One Ethylene Acetate Copolymer ¹⁾ 30 60 100 Ethylene Acrylic Rubber ²⁾ 23 15 - Ethyleneacrylic copolymer ³⁾ 12 5 - Alpha-olefin copolymer ⁴⁾ 35 20 - Polylactic acid copolymer ⁵⁾ - 5 - Adhesion Enhancer ⁶⁾ 5 5 - ZnO ⁷⁾ 3 3 3 St / A ⁸⁾ One One One TiO ₂ ⁹⁾ 4 4 4 U / Blue M / B ¹⁰⁾ 0.5 0.5 0.5 DCP ¹¹⁾ 0.7 0.8 0.625 TAC ¹²⁾ 0.5 0.5 0.5 JTR ¹³⁾ 3.3 3.8 3.0 1) ELVAX3388, Dupont (USA)
3) Elvaloy3427AC, Dupont (USA)
5) Polylacticacid, Natural works (USA)
7) Zinc oxide, Gilcheon
9) Titanium oxide, Dupont (USA)
11) Dicumyl peroxide (crosslinking agent)
13) Modified ADCA system (JTR, blowing agent) 2) Ethylene acrylic rubber, Dupont (USA)
4) GMH, sumitomo (JAPAN)
6) Adhesive Enhancer
8) Stearic Acid, LG Chemical
10) Pigment, Ultramarine blue, ICl. (England)
12) Triallyl Cyanurate

2. Test method

Physical properties of the foams for shoe soles prepared by Examples 1 and 2 and Comparative Example 1 were measured in the following manner, and the results are shown in the following [Table 2].

1) Specipic gravity

The specific gravity of the foam was measured five times using an automatic specific gravity measurement after removing the surface and the average value was taken.

2) Hardness

Hardness was measured in accordance with ASTM D-2240 with an esker C hardness tester on the foam surface.

3) Tensile strength and elongation

After making the thickness of the foam to 3mm, the test piece was made with a Die A cutter and measured according to ASTM D-412. At this time, five test pieces were used for the same test, and the tensile speed was 200 mm / min.

4) Tear strength

The tear test was measured according to ASTM D-3574 and ASTM D-634, respectively, and the measurement speed was measured five times at 200 mm / min, and the average value was taken.

5) Split tear strength

The tear tear strength test was made with 5 test specimens (10 × 25 × 100mm) used in the same test to measure the tear tear strength, except that more than 20% of the median value was measured.

6) Compression set

The test piece manufactured in the form of a cylinder having a diameter of 28.7 ± 0.05 mm by turning the foam to 10 mm in thickness was measured according to ASTM D-3547. Place the specimen between two parallel metal plates, insert a spacer equal to 50% of the specimen thickness, compress it, heat it in an air-circulating oven maintained at 50 ± 0.1 ° C for 6 hours, and remove the specimen from the compression device. After cooling for 30 minutes at room temperature the thickness was measured. Three test pieces were used in the same test, and the compression reduction rate was calculated by Equation 1 below.

Cs (%) = (t ₀ -t _f ) / (t ₀ -t _s ) x 100... … (Equation 1)

In Equation 1, Cs is the compression permanent reduction rate, t ₀ is the initial thickness of the test piece, t _f is the thickness of the test piece when cooled after heat treatment, and t _s is the thickness of the spacer.

7) Adhesion strength measurement (90 ° peeling strength measurement method)

The adhesive strength of the foam was tested by measuring the peel strength. The number of test pieces was 3, and after 1 day of adhesion, the result was measured at a speed of 100 mm / min using a universal testing machine (UTM, Zwick model 1435) and averaged. .

Characteristics Example Comparative example One 2 One Expansion ratio 162 162.5 160 importance 0.197 0.187 0.181 Hardness 56-57 59-60 60 Tensile Strength (kg / cm ² ) 30.3 / 30.2 31.6 / 31.0 23.0 Elongation (%) 280/300 460/470 220 Tear strength (kg / cm) 14.2 / 14.3 17.6 / 17.8 7.8 Rupture Tear Strength (kg / cm) 2.5 3.2 1.7 Compressed permanent reduction rate (%) 47 63 51 Adhesive strength
(kg / cm) Non-UV Process 3.0-3.5 * ↑ 4.5 ~ 5.0 * ↑ 0.2

Note) *: Indication that the adherend is broken. Generally, the adhesion of the material is completely occurred, which means that the material is destroyed from the surface to the inside.

As shown in Table 2, the shoe sole foams of Examples 1 to 2 according to the present invention have superior mechanical strength, such as tensile, tear, and tear tear strength, as compared to the shoe sole foam of Comparative Example 1. Compressive permanent shrinkage is also excellent and the adhesive properties by effectively responding to the plasma also showed the adhesive strength of 2.5kg / cm or more required in the existing industry, it was confirmed that complete adhesion.

1A and 1B are attached to a reference SEM image of the shoe midsole foam for Example 1 according to the present invention, Figures 2A and 2B is a shoe midsole foam for Example 2 according to the present invention 3 is a SEM photograph, and FIGS. 3A and 3B relate to SEM photographs of foams for shoe midsoles of Comparative Example 1 for contrasting with Examples 1 and 2. FIG.

As shown in the accompanying photo, in the case of the pictures of the shoe midsole foam of Example 1 and Example 2 according to the present invention, the state of the surface is curved and irregularities are formed compared to the picture of the shoe midsole foam of Comparative Example 1 It is a favorable state for adhesion.

4 is an IR graph analyzing the surface of the shoe midsole foam for Example 1 according to the present invention, and FIG. 5 is an IR graph analyzing the surface of the shoe midsole foam for Comparative Example 1. 4 and 5 show large peaks not shown in FIG. 5 at 1508.71 (cm ⁻¹ ) and 1161.10 (cm ⁻¹ ) in FIG. 4. The peak of 1508.71 is -COOH and is considered to be -COOH of ethylene acrylic rubber. 1161.10 The peak is COO- or CO, Si-O, Si-H peak (peak) is determined by the adhesion improving agent. It is judged that these peaks show polarity, thereby improving adhesion.

For reference, FIGS. 6A to 6C of the accompanying drawings relate to a photograph of the shape of a shoe sole foam when the polylactic acid content exceeds 15 parts by weight, and the polylactic acid content is determined by the same method as in Comparative Example 1. In the photograph of the shape of the shoe sole foam produced to exceed 15 parts by weight, in the case of Figure 6a is molded by increasing the molding time, and molded in the general injection molding conditions of Figure 6b, in the case of Figure 6c It is a shape when the content of polylactic acid is 40 parts by weight. As shown in the figure, if the amount of polylactic acid used exceeds the usage range, it can be seen that the shape of the foam is not normally formed.

As described above, the present invention has been described the superiority of the present invention through preferred embodiments, but those skilled in the art will be able to vary the present invention without departing from the spirit and scope of the invention as set forth in the claims below. It will be appreciated that modifications and variations can be made.

1A and 1B are SEM images of the foam for shoe soles for Example 1 according to the present invention,

Figures 2a and 2b is a SEM photograph of the shoe midsole foam for Example 2 according to the present invention,

3a and 3b is a SEM photograph of the foam for the shoe midsole for Comparative Example 1 to contrast with Examples 1, 2,

Figure 4 is an IR graph analyzing the surface of the shoe sole foam for Example 1 according to the present invention,

5 is an IR graph analyzing the surface of the shoe sole foam for Comparative Example 1,

6A to 6C relate to a photograph of the shape of the shoe sole foam when the polylactic acid content exceeds 15 parts by weight.

Claims (7)

A foam composition for shoe midsoles, 2.5 to 7.0 parts by weight of foaming agent and 0.5 to 0.8 weight of crosslinking agent based on 100 parts by weight of a mixed substrate blend of ethylene vinyl acetate copolymer, ethylene acrylic copolymer, alpha-olefin copolymer and ethylene acrylic rubber Part, 0.5 to 1.0 parts by weight of crosslinking aid, 1 to 5 parts by weight of metal oxide, 1 to 2 parts by weight of stearic acid, 0.1 to 1.0 parts by weight of pigment, 1 to 5 parts by weight of titanium oxide, and 5 to 10 parts by weight of adhesion improving agent Non-UV adhesive compound foam composition for shoe soles. The method of claim 1, The mixed substrate blend is 30 to 60 parts by weight of ethylene vinyl acetate copolymer, 5 to 12 parts by weight of ethylene acrylic copolymer, 20 to 35 parts by weight of alpha-olefin copolymer and 15 to ethylene acrylic rubber. Foam composition for non-UV adhesive shoe soles, characterized in that consisting of 23 parts by weight. The method of claim 1, A non-UV adhesive compound composition for shoe soles, characterized in that it further comprises 1 to 15 parts by weight of the polylactic acid copolymer with respect to 100 parts by weight of the mixed substrate blend. In the manufacturing method of the foam for shoes midsole, 1) 2.5 to 7.0 parts by weight of blowing agent, 0.5 to 0.8 parts by weight of crosslinking agent, 0.5 to 1.0 parts by weight of crosslinking aid, 1 to 5 parts by weight of metal oxide, 1 to 2 parts by weight of stearic acid, pigment 0.1 based on 100 parts by weight of the mixed substrate blend. Preparing a compound for shoe sole foam in a pellet form capable of injection molding through ~ 1.0 parts by weight, 1-5 parts by weight of titanium oxide, and 5-10 parts by weight of an adhesion improving agent through a kneader; 2) by injection molding the compound prepared in step 1) at 170 ~ 172 ℃, 140 ~ 160 kg / cm ² for 6 to 8 minutes to produce a shoe sole foam, or 2 ') The foam prepared by first pressing the compound prepared in step 1) at 150 to 170 ° C. and 140 to 160 kg / cm ² for 11 to 15 minutes at 150 to 160 ° C. and 140 to 160 kg / cm ² . Method for producing a shoe midsole foam using a non-ultra-adhesive shoe midsole foam compound composition, characterized in that the step of producing a foam for shoe midsole by cold compression after the second press. The method of claim 4, wherein The mixed substrate blend of step 1) comprises 30 to 60 parts by weight of ethylene vinyl acetate copolymer, 5 to 12 parts by weight of ethylene acrylic copolymer, 20 to 35 parts by weight of alpha-olefin copolymer and ethylene Method for producing a foam for shoe soles using a non-ultraviolet adhesive foam compound composition for non-ultraviolet adhesion, characterized in that consisting of 15 to 23 parts by weight of the acrylic rubber. The method of claim 4, wherein Preparation of shoe soles using a non-ultraviolet adhesive foam compound composition for non-ultraviolet adhesion, characterized in that it further comprises 1 to 15 parts by weight of the polylactic acid copolymer with respect to 100 parts by weight of the mixed substrate blend in step 1) Way. Shoe midsole foam prepared by the method of any one of claims 4 to 6 for non-ultra-adhesive shoe soles, characterized in that the adhesive is applied only after the primer treatment without going through the ultraviolet (UV) irradiation process Method for producing a foam for shoe midsole using the foam compound composition.

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